Pokémon Brick Bronze Wikia:Rarity Scale

Almost all locations in Roria provide Wild Pokémon to encounter. Pokémon Brick Bronze Wikia has a Rarity Scale set up to classify Pokémon into different rarity levels.

Scale and Sample Size
For at least each 200 encounters, assign the rarity level of a Pokémon as follows: You are also allowed to increase the sample size to 500 or even 1000 encounters if you have the time to do so. Multiply the scale proportionally such that test results follow the percentage, as shown above. Any rarity levels out of the above 4, like "Super Rare" or "Ultra Rare", are not allowed.

However, there is a standalone article listing out all Roaming Pokémon, so please exclude Roaming and Event Pokémon from the encounter rate assessments and Wild Encounter templates in location pages.

Special Encounters
For special encounters which only provide one chance for battle, such as Mythical Pokémon Jirachi, they are automatically labelled as One Only via the Set Encounter templates.

Another kind of special encounters are only available once per week. Replace the rarity level with corresponding day of the week such as "Friday", so that the template will automatically show "Every Friday".

Some Pokémon only appear during the day or at night, please attach " " or " " respectively.

Official Encounter Rates
There are also a few Pokémon which have their exact encounter rates confirmed by the main developers. The exact encounter rates are listed in red directly below the rarity level, via the code " ". Please do not change them unless the developers announced that those encounter rates have been modified.